When the fin whale gets ready to eat, Earth's second-largest animal opens its mouth so wide that it can gulp an amount of water larger than the volume of its own body as it filters out meals of tiny fish and shrimp-like krill.
When feeding, this whale measuring up to about 88 feet (26.8 meters) long and 70 tons increases its swimming speed, opens its mouth and lunges in the ocean.
The force of water rushing into the mouth during "lunge feeding" turns the tongue upside down and expands the bottom of the oral cavity into a huge pouch between the body wall and the overlying skin and blubber. As it closes its mouth, the whale filters out seawater through plates in the mouth while eating huge quantities of small prey.